FAILURE ANALYSIS OF TAPPING SCREWS FRACTURE FOR ENGINEERING APPLICATION
Self-drilling screw of φ10mm broken off after assemblage, and there were also a few screw fractured during embrittlement test for this lot products. In this paper metallograph, fracture and microhardness were tested and analyzed. The examination results showed that the fracture character were mainly brittle fracture with intergranular fracture form. The carburization penetrated the section between head and shank, and the microhardness test proved that the strength in the fracture area exceeded that of 10.9 bolt as the micrhardness exceeded 40HRC, which directly resulted in increasing greatly fracture sensitive hydrogen induced. According above, the fracture was caused by hydrogen embrittlement in conjunction with higher microhardness of fracture area and lower toughness resulted from carburization . Finally the improving suggestions were put forward and applied.
Fahai Ba Guoqiang Yan
Bafahai, male, PHD, Shanghai Research Institute of Material, Shanghai, 200437, P.R.China, Engage in materials failure analysis
国际会议
第九届工程结构完整性国际会议(The Ninth International Conference on Engineering Structural Integrity Assessment)
北京
英文
2007-10-15（万方平台首次上网日期，不代表论文的发表时间）